Magnesium Glycinate vs Vitamin B6 (P5P)

Mechanism

Magnesium is a cofactor for >600 enzymatic reactions including all ATP-dependent reactions (Mg-ATP is the true substrate), DNA/RNA polymerases, and ion channel regulation. Magnesium glycinate chelate provides highly bioavailable elemental magnesium bound to glycine. The glycine moiety itself is an inhibitory neurotransmitter (glycine receptors) and NMDA receptor co-agonist at the glycine binding site. The chelated form minimizes the osmotic laxative effect of ionic magnesium salts. Magnesium regulates NMDA receptor gating (voltage-dependent Mg2+ block), GABA-A receptor potentiation, HPA axis modulation, and parathyroid hormone secretion.

Standard Dosing

200-400mg elemental magnesium daily

Timing

Evening/bedtime (promotes relaxation and sleep quality). Can split AM/PM.

Cycle Duration

ongoing

Side Effects

• Drowsiness
• Mild GI discomfort
• Loose stools (less than other Mg forms)
• Hypotension at very high doses

Contraindications

• Severe renal insufficiency (impaired Mg excretion — risk of hypermagnesemia)
• Myasthenia gravis (Mg can worsen neuromuscular junction blockade)
• Heart block (Mg slows AV conduction)

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Mechanism

Pyridoxal-5-phosphate (P5P) is the active coenzyme form of vitamin B6, required by over 150 enzymes. Key roles: transamination and decarboxylation of amino acids, serving as a cofactor for aromatic L-amino acid decarboxylase (converting 5-HTP to serotonin and L-DOPA to dopamine), glutamic acid decarboxylase (producing GABA), cystathionine beta-synthase (homocysteine transsulfuration to cysteine), serine hydroxymethyltransferase (one-carbon folate metabolism), glycogen phosphorylase (glycogenolysis), and aminolevulinic acid synthase (heme synthesis).

Standard Dosing

25-50mg P5P daily

Timing

Morning with food. Often included in B-complex.

Cycle Duration

ongoing

Side Effects

• Peripheral neuropathy at chronic doses >200mg/day (numbness, tingling)
• Photosensitivity
• Nausea
• Vivid dreams

Contraindications

• Levodopa monotherapy
• Doses >200mg/day chronically (peripheral neuropathy risk)

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